局部晚期胰腺癌调强放疗与三维适形放疗剂量学比较及临床疗效分析

A dosimetric comparison of three-dimensional conformal and intensity-modulated radiotherapy inlocally advanced pancreatic cancer and a study of the clinical efficacy

目的 比较局部晚期胰腺癌放疗中三维适形放疗（3 D-CRT）与调强放疗（IMRT）技术的剂量学差异,观察IMRT联合吉西他滨局部化疗的临床疗效.方法 选择10例局部晚期胰腺癌患者的CT定位图像,分别设计3D-CRT和IMRT计划,利用剂量体积直方图（DVH）评价2种治疗计划的剂量.回顾性收集2008年5月至2010年5月符合入组标准的25例接受IMRT联合吉西他滨局部介入治疗的局部晚期胰腺癌患者（联合治疗组）,选择同时期入院的仅接受吉西他滨局部介入治疗的25例晚期胰腺癌患者（单化组）做对比研究,比较2组的临床疗效及不良反应.结果 IMRT计划中十二指肠、肝脏、胃、双肾、小肠的平均剂量及高剂量区照射体积明显低于3D-CRT计划.联合治疗组与单化组1、2年生存率分别为60％、28％和36％、12％,中位生存期分别为15个月和10个月（x2 =4.16,P＜0.05）,有效率分别为64％和32％（x2 =5.13,P＜0.05）.联合治疗组上消化道反应发生率高于单化组（Z=-2.35,P＜0.05）,而骨髓抑制、肝肾功能损害情况差异无统计学意义.结论 与三维适形放疗相比,调强放疗在保证靶区高剂量的情况下降低危及器官的剂量,联合吉西他滨局部化疗可显著提高局部晚期胰腺癌患者的生存率,延长的中位生存时间,且不良反应轻微.

Objective To compare the dose distribution between three-dimensional conformal radiotherapy（3D-CRT） and intensity-modulated radiotherapy （IMRT） in treating locally advanced pancreatic cancer, and report the efficacy of IMRT combined with regional chemotherapy using gemeitabine （GEM）. Methods Ten patients with locally advanced pancreatic cancer were enrolled in this study. 3D- CRT and IMRT plans were designed for each patient. The dose distributions of target volume and normal tissues were analyzed using the dose volume histogram （DVH）. Twenty-five locally advanced pancreatic cancers patients who were treated by IMRT combined with regional chemotherapy using gemcitabine （ combined group） were retrospective analyzed, as well as 25 hospitalized patients of the same period who were treated by regional chemotherapy using gemeitabine alone （chemotherapy alone group ）. The therapeutic efficacy and adverse events were compared between two groups. Results IMRT plans decrease the mean dose and volume of duodenum, liver, stomach, both kidney and small bowel that received high- dose irradiation. The 1-,2-year survival rate of the combined group and chemotherapy alone group was 60% ,28% and 36% , 12%. The median survival time of two groups was 15 and 10 months, respectively （X2 =4.16 ,P 〈0.05 ）. The total response rate of the combined group and the chemotherapy alone group was 64% and 32% , respectively （X2 = 5.13, P 〈 0.05 ）. The upper gastrointestinal side-effect rate of the combined group was higher than that of the chemotherapy alone group （ Z = -2. 354, P 〈 0.05 ）. There was no statistic significance in hematologic toxicity, liver and renal functional damage between the two groups. Conclusions Compared with 3D-CRT plan, IMRT plan could reduce the dose of organ at risks. IMRT combined with regional chemotherapy using gemcitabine could significantly improve the survival rate of patients with locally advanced pancreatic cancer with mild adverse events.